Wellhead constructions



Au 22,- 1967 w. w. WORD, JR 3,336,976

WBLLHEAD CONSTRUCTIONS Filed Sept. 20,

5 Sheets-Sheet l INVENTOR William w. Word,Jr.

FIG.I.

ATTORNEYS Aug. 22, 1967 w. w. WORD. JR

WELLHEAD CONSTRUCTIONS Filed Sept. 20, 1963 5 sheets Sheet- 2? INVENTORWilliam W. Word,Jr.

BY M.

ATTOR NEYS Aug. 22, 1967 w. w. woRb, JR 3,336,976

FIG.'3.

INVENTOR William W. Word,Jr

ATTORNEYS Aug. 22, 1967 w. w. WORD, JR

5 Sheets-$heet 4 FIG.'5.

INVENTOR William W. Word,Jr.

- BYQ gzwurfi b FIG].

. ATTORNEYJ Aug. 22, 1967 w. w. WORD, JR 3,336,976

WELLHEAD CONSTRUCTIONS Filed Sept. 20, 1963 5 Sheets-Sheet f f 65 J H;

IZH! 5 39 f I I22 I 38 9s 3 l2 l gfs 5 n3 2 as 3 H I8 I U f 23 2s 2 2el4 l I g y I I I l I I IHIHTEIIH 3 3 INVENTOR FIG 6 William W. Word,Jr.

ATTORNEYS- United States Patent Ohio Filed Sept. 20, 1963, Ser. No.310,367 Claims. (31. 166-.6)

This invention relates to well apparatus and particularly to wellheadconstructions. Though of broader utility, the invention is especiallydirected to solving problems involved in the installation of wellheadconstructions under water.

Wellhead constructions serve to position and support casing, tubing andthe like upright elongated members which extend down the bore hole, toseal off the top of the well, and to conduct various fluids incontrolled fashion. Further, wellhead constructions must becharacterized by substantial flexibility of purpose, since they areemployed at operational stages ranging from drilling to production.Through long years of development, various types of wellheadconstructions have, to a considerable extent, become more or lessstandardized insofar as general structural features are concerned,though there are relatively modern problem areas which, like multiplecompletion wellhead installations, have stimulated present-day advancesof fundamental importance. At the present time, the industry isundertaking the installation of wells under novel conditions presentingproblems which differ both in kind and in severity from the problemsencountered in every-day well practice. These conditions are encounteredin the establishment of producing wells drilled in the floor of a bodyof water, with the wellhead construction usually installed substantiallyat the floor of the body of water and therefore remote from the surfaceby a distance which may range from less than 100 feet to as much as15,000 feet.

In the case of a wellhead installation on dry land, all of theoperational wellhead parts are either visible or accessible withrelative ease. Hence, for example, if a hanger element secured to acasing string is to be lowered into the wellhead, so as to seat properlyon a supporting member, this operation presents relatively littledilficulty because the descent of the hanger element can be observed inrelation to the wellhead body and the supporting member. Further, it isa relatively simple matter to back off the casing string and try againwhen necessary. Similarly, the problems of obtaining proper alignmentbetween body members, and between sealing elements and bores, forexample, are greatly simplified at ground level because of the relativeease with which the parts can be observed and manipulated manually.Problems of attaching one member to another, as in the case of securingan upper head member to the top of a lower head member, are also handledwith relative case at ground level.

When the wellhead construction is to be installed at a considerabledepth under water, however, even those problems which are simple atground level become exceedingly difficult. It is obviously impractical,for instance, to consider bolting two head members together at depthsbelow the surface of the sea greater than attainable by a diver.Similarly, the problems of properly seating a member in the body of awellhead at such a depth has been likened to threading a needle at fiftypaces in the dark.

A broad objective of this invention is to device an improvedconstruction for installing and suspending upright elongated members,such as casing and tubing, in a well.

Another object is to provide an improved, more effective and dependable,wellhead construction.

A further object is to provide a wellhead construction, especiallysuited for underwater installation, wherein casing or the like can besuspended successfully even though, because of jamming or otherwise, thecasing is not lowered fully to the intended position.

Yet another object is to devise a wellhead or like apparatus forsuspending casing, tubing, and the like, which provides, in addition toa fixed-shoulder or equivalent supporting means, an alternativelyuseful, normal inactive slip assembly which can be brought intoeffective operation by remotely controllable power means situated at thewellhead.

In order that the manner in which these and other objects are attainedin accordance with the invention can be understood in detail, referenceis had to the accompanying drawings, which form a part of thisspecification, and wherein:

FIGS. 1 and 1A constitute a view, partly in vertical section and partlyin vertical elevation, of an underwater Wellhead construction inaccordance with one embodiment of the invention, illustrating casing andtubing strings supported by shouldered hanger mandrels, only afragmentary portion of the upper body member of the wellheadconstruction being shown;

FIG. 2 is a transverse sectional view, taken on line 22, FIG. 1A;

FIG. 3 is a view, partly in vertical section and partly in verticalelevation, of the lower one of two hanger members employed in thewellhead construction of FIGS. 1 and 1A;

FIG. 4 is a transverse sectional view taken on line 4-4, FIG. 1A;

FIG. 5 is a view, partly in vertical section and partly in elevation, ofone of the hanger mandrels employed in the wellhead construction ofFIGS. 1 and 1A;

FIG. 6 is a view, similar to FIG. 1A, showing the wellhead constructionwith one casing string supported by slips and the upper end of thatcasing string packed off in accordance with the invention; and

FIG. 7 is a view, partly in vertical section and partly in elevation, ofthe seal or pack-off device employed in the construction seen in FIG. 6.

FIGS. 1-7 illustrate a wellhead construction which is particularlyadapted for successful installation at considerable depths under water.In this embodiment, the wellhead construction comprises a lower bodymember 1 attached in sealed relation to the upper end of an outer casing2. As will be apparent from FIGS. 1 and 1A, this wellhead constructionis adapted to support, under various conditions of installation and use,a surface casing 3, a production casing string 4, and a tubing string 5.At its upper end, lower body 1 supports an upper body member 6. Lowerbody member 1 has a vertical through bore, indicated generally at 7,which accommodates a lower hanger member 8- and an upper hanger member9. Both hanger members 8 and 9 cooperate with a set of selectivelyactuatable, power operated slips, described in detail hereinafter.Additionally, when employed in the manner seen in FIGS. 1 and 1A, lowerhanger member 8 supports a lower hanger mandrel 10 while upper hangermember 9 supports an upper hanger mandrel 11 surface casing 3 being hungfrom the lower hanger mandrel 10 while production casing string 4 ishung from the upper hanger mandrel 11.

The upper body member 6 is also provided with a vertical through boreindicated generally at 12 which is vertically aligned with through bore7 of lower body 1. The tubing string 5 is suspended from a supportmember 13 mounted in the' lower end of bore 12.

Suspension casing 3 Immediately above the upper end of outer casing 2lower body 1 is provided with a pair of opposed laterally directed ports14. Above these ports the diameter of through bore 7 is markedlyincreased to provide an upwardly facing downwardly and inwardly slantingannular shoulder 15. Save for porting and ducting hereinafter describedbore 7 extends as a plain cylinder upwardly from shoulder 15.

Lower hanger member 8 is of tubular form and is provided at its lowerend with a frusto-conical end face of such shape as to seat inface-to-face contact with shoulder 15. Thus, engagement of the lower endface 16 of hanger member 8 on shoulder provides rigid support for thelower hanger member, as seen in FIG. 1A. Adjacent its lower end, theinner surface of member 8 is cut away to provide a downwardly andinwardly slanting, frusto-conical, slip-supporting surface, indicated at17. Immediately above surface 17, the wall of tubular member 8 issubstantially greater in thickness than it is at the top of the surface17, so as to provide an intermediate body portion 18 which can beconsidered as joined to the slip-supporting surface 17 by a transverselyextending shoulder 19. The upper end of intermediate body portion 18 isdefined by a transverse, annular shoulder 20 slanting downwardly andinwardly and lying parallel to the bottom end face 16. Above shoulder20, upper portion 40 of member 8 is of reduced thickness, so as toaccommodate hanger mandrel 10 in the manner hereinafter described.

Intermediate body portion 18 of member 8 is provided with at least threeequally and circumferentially spaced downwardly opening verticalcylinder bores directed generally toward slip-supporting surfaces 17,each of'these bores slidably accommodating a cylindrical plunger 21. Alaterally extending, outwardly opening port leads to the upper end ofeach of the cylinder bores and, as will be seen in FIG. 1A, the lengthof the plungers 21 is such that, when their lower ends are substantiallyflush with shoulder 19, their upper ends engage the upper ends of thecylinders which accommodate them and are disposed to be acted upon byhydraulic fluid supplied through the ports 22. It will be noted that theupper end of each plunger 21 is tapered, providing a surface againstwhich hydraulic fluid supplied via port 22 can act downwardly toinitiate downward movement of the plunger. Each plunger 21 is providedwith a groove carrying an O-ring to provide a seal between the plungerand the wall of the bore accommodating the same.

In the region of slip-supporting surface 17, member 8 is provided withthree circumferentially and equally spaced vertical slots 23, each suchslot opening outwardly into an outwardly opening recess 24. Slidablydisposed on surface 17 is a slip assembly consisting of three identicalslip segments 25. Each segment 25 is in the form of a downwardlytapering wedge-like member having a frustoconical outer surface of suchsize and shape as to lie in flush face-to-face contact with surface 17'.Each segment has a toothed, or otherwise suitably interrupted, inwardlydirected working face 26 and an upwardly exposed transverse end face 27which extends below one of the plungers 21. On its outer face, eachsegment 25 is provided with a vertically extending, radially outwardlyprojecting guide flange 28 slidably disposed in the corresponding slot23. The flange 28 cooperates with its slot 23 to accurately guide theslip segment in its vertical movement along supporting surface 17. Thus,the slot 23 can have vertical side walls and flange 28 can be ofrectangular transverse cross section so as to present side walls insliding engagement with the side walls of the slot. A pair of verticallyspaced retaining elements 29 are threaded or otherwise suitably securedin guide flange 28 and have enlarged head portions disposed in recess24, the space between the en larged heads of elements 29 and theoutwardly facing shoulders between slot 23 and recess 24 is filled by anassembly of spring washers, or any other suitable elements, so thatelements 29 function to retain slip segment 25 in sliding engagementwith the surface 17. In this connection, it will be noted that the innerwall of recess 24, which forms the shoulders at the slot 23, is disposedparallel to surface 17, so that slot 23 is of constant depth.

At least one inwardly projecting shear pin 30 is secured in member 8 foreach slip segment 25 and is spaced below shoulder 19 by a distance onlyslightly greater than the vertical length of the slip segment. Shearpins 30 project inwardly from surface 17 and hold the segments 25 in araised, inactive position, so that the working faces 26 of the slipsegments will be spaced outwardly from the casing member which they mayultimately be called on to support. With the segments in raisedposition, the upper end face 27 of each slip segment will lie in contactwith the lower end of the corresponding one of plungers 21. It will thusbe apparent that, if hanger member 8 is seated, with its lower end 16 incontact with shoulder 15 of member 1, the slip segments 25 will normallybe held in raised, inactive position by the shear pins 30 but can bedriven downwardly, sliding along surface 17, if sufiicient hydraulicpressure is applied, via ports 22, to cause plungers 21 to apply adownward force to the slip segments which is adequate to break shearpins 30. Each segment 25 carries a pin 30', FIG. 2, which projects intoa bore in the adjacent segment, the bore being of slightly largerdiameter than the pin. Thus, if one segment is forced downwardly tobreak its shear pin 30 before the other segments, the pins 30' willprevent further major downward travel until all of shear pins 30 havebeen broken and all of the segments can descend together.

Near its lower end, each slip segment 25 is interrupted by a deformablebody of packing material which extends completely through the slipsegment from the working face thereof to the outer face which engagessupporting surface 17. Indicated at 31, this packing is capable ofproviding a fluid-tight seal between the outer surface of casing 3 andsupporting surface 17. Packing 31 can be provided in any suitablefashion, as by making the same in the form of a joint between twoseparate metal portions making up the body of the slip segment, thepacking material being adhesively bonded to the metal.

Lower end 16 of member 8 is provided with at least one upwardly andinwardly inclined bore which accommodates a locator pin 32. Pin 32 isurged outwardly, so as to project from the surface of end 16, by acompression spring disposed within the bore and is retained within thebore by a snap ring seated in a suitable groove in the wall of the boreadjacent the mouth thereof. Shoulder 15 is provided with a circularlyextending transverse groove 33 so located that, when the lower end 16 ofmember 8 is seated on shoulder 15, locator pin 32 will project intogroove 33. Groove 33 is of generally V-shaped transverse cross section,with the lower wall of the groove extending substantially horizontallyand with the upper wall inclined at the same angle as is the bore forlocator pin 32. Spaced from the bottom of the V of groove 33, anupwardly extending ridge or flange 34 projects from the lower wall ofgroove 33. Flange 34 is provided with a notch capable of snuglyembracing locator pin 32. Hence, when member 8 is lowered into seatedposition on shoulder 15, it can be rotated until locator pin 32 fallsinto the notch in flange 34. When that occurs, member 8 will berotationally located with respect to body 1 in such fashion that anygiven point on the outer surface of member 8 will be radially alignedwith a definite point on member 1. With this in mind, it will be notedthat a laterally extending through port is provided in the wall ofmember 1, as indicated at 35, at a position such as to be aligned withone of the ports 22 when locator pin 32 is disposed in the notch inridge or flange 34. Of course, a plurality of ports 35 are provided, onefor each of the ports 22. Further, the inner surface of member 1 isprovided with a shallow, inwardly opening,

circularly extending transverse groove 36 which interconnects the innerends of ports 35. At points which will lie respectively above and belowgroove 36, when member 8 is seated on shoulder 15, member 8 istransversely grooved and provided with annular packings 37 held incompression between member 8 and body 1 to seal oif the area of ports 35and make certain that hydraulic pressure applied through these ports isconducted to ports 22.

At a point spaced above ports 35, at least one larger laterally directedthrough port 38 is provided in the wall of member 1. Member 8 isprovided with a through port 39 which is coaxially aligned with port 38,when member 8 has been rotationally located in proper position bylocator pin 32.

The upper portion 40 of member 8 presents a circularly extending,transverse, downwardly and inwardly slanting surface 40' which, as willbe later described, acts as a shoulder to support upper hanger member 9.

Lower hanger mandrel is of tubular form, the lower end thereofpresenting a circularly extending, transverse, downwardly and inwardlyslanting surface 41 adapted to seat in flush, face-to-face contact withthe upwardly directed shoulder presented by member 8. At its bottom end,hanger mandrel 10 is interiorly threaded for rigid connection to theexteriorly threaded upper end of surface casing 3. Adjacent the lowerend thereof, hanger mandrel 10 is provided, at its outer surface, with apair of circularly extending, transverse grooves containing O-ring sealsfor engagement with a cylindrical inner surface provided by the portionof member 8 above shoulder 20. It will thus be understood that hangermandrel 10 can be threadedly attached to the upper end of the lastlength of casing 3 installed and, as this length of casing is loweredthrough body 1 so that the lower end of the hanger mandrel seats onshoulder 20, the casing string 3 will then be rigidly supported on body1, via member 8, and a fluidtight seal will be effected between hangermandrel 10 and body 8, and hence between casing 3 and member 8, by theO-ring seals 42.

At a point spaced well above its lower end, mandrel 10 is provided witha least one lateral bore slidably accommodating an outwardly biasedlatch pin 43 in the manner described and claimed in Patent 3,171,674,issued Mar. 2 1965, to Paul E. Bickel and William W. Word, Jr. In themanner fully described in said patent, pin 43 is urged outwardly by acompression spring accommodated behind the same and is retained in placeby a catch of any suitable form. Pin 43 is provided with a short tip ofsmaller diameter than the bore which accommodates the locator pin, thetip being connected to the main body of the pin by a portion presentingan upwardly facing downwardly and outwardly slanting camming surface 43.At a distance above shoulder 20 suitable for receiving pin 43 whenhanger mandrel 10 is seated on shoulder 20, the inner surface of member8 is provided with a transverse annular groove 44 into which theprojecting tip of pin 43 can extend when the hanger mandrel is in properseated position. Groove 44 is provided with a radial locator stop (notshown) disposed to be engaged by pin 43. Hence, when mandrel 10 islowered into place, and so seats on shoulder 20, pin 43 snaps intogroove 44 and rotation of the mandrel can bring pin 43 into engagementwith the locator stop, thus rotationally locating the hanger mandrelwith reference to member 8. From FIG. 1A, it will be noted that thisrotational location serves to align a lateral through port 45, providedin mandrel 10, with the through port 39 in member 8 and, hence, withport 38 in body 1. Thus, the interior of casing string 3 is placed incommunication with port 38. The vertical length of hanger mandrel 10 issuch that the upper end thereof is disposed slightly below end sur face40' of member 8 when the hanger mandrel is seated on shoulder 20 as seenin FIG. 1A.

Suspension of casin'g string 4 Upper hanger member 9 is similar tomember 8 and includes a circularly extending, transverse, downwardly andinwardly tapering lower end face 46 of such extent and configuration asto come into flush, face-to-face contact with the upwardly directed face40 provided at the upper end of hanger member 8. Thus, assuming hangermember 8 to be in place, as seen in FIG. 1A, lowering of upper hangermember 9 into body 1 will bring lower end face 46 of member 9 intoseated engagement with the upper end face of lower hanger member 8.Member 9, presents a circularly extending, downwardly and inwardlyslanting, frusto-conical slip-supporting surface 47 and has a verticallyshort intermediate body portion 48, portion 48 presenting a downwardlydirected, outwardly inclined, transverse face 49 which lies at rightangles to the slipsupporting surface 47. Intermediate body portion 48also presents an upwardly directed, downwardly and inwardly inclined,circularly extending face 50 disposed to support the upper hangermandrel 11.

Hanger member 9 carries a slip assembly comprising three transverselyarcuate slip segments 51 of generally wedge-shaped vertical crosssection. Each slip segment 51 presents an inwardly directed, interruptedworking face 52, an arcuate outer face of such configuration as toslidably engage supporting surface 47, and a flat upper end face 53which extends at right angles to supporting surface 47. Member 9 isprovided with three vertically extending guide slots 54, each arrangedto cooperate with one of the slip segments 51, and each openingoutwardly into a recess 55, in similar fashion to the correspondingelements described with reference to member 8. Each slip segment 51 isprovided with a vertically extending, upwardly projecting guide flange'56 which is slidably disposed in the corresponding one of guide slots'54. A pair of vertically spaced retaining elements 57 have their innerends secured in the guide flange 56 and include enlarged head portionsdisposed in recess 55. Spring washers or other suitable spacing meansare disposed between the enlarged heads of retaining elements 57 and theshoulders formed by guide slots 54, the inner face of recess 55 againextending parallel to the slip-supporting surface so that the retainingelements serve to maintain slip segment 51 constantly in slidableengagement with the slipsupporting surface.

A plurality of cylinder bores, including at least one for each slipsegment 51, are formed in member 9 in such fashion as to open throughface 49 and to be disposed parallel to slip-supporting surface 47, eachsuch bore accommodating a cylindrical plunger 58. A generally lateralduct 59 is provided for each cylinder bore, so that hydraulic pressurecan be applied to the upper ends of the plungers 58 in substantially thesame fashion hereinhefore described with reference to operation ofplungers 21. It will be seen that each plunger 58 is disposed to movealong a line at right angles to the flat upper end face of thecorresponding one of slip segments 51, this line of movement beingparallel to slip-supporting surface 47.

Member 9 carries at least one shear pin for each slip segment 51, asindicated at 60, the shear pins 60 being disposed for engagement by thelower edges of the slip segrnents. Thus, shear pins 60 serve to hold theslip segments in a raised, inactive position, in which position theyengage the lower ends of plungers 58. It will be obvious from FIG. 1Athat, when adequate hydraulic pressure is applied to the plungers viaducts 59, the plungers will operate to force slip segments 51downwardly, breaking shear pins 60,'so that the slip segments can comeinto good supporting engagement with the outer surface of casing 4. Asdescribed with reference to suspension of easing string 3, slip segments51 are each provided with a suitable packing 61 to efiect a fluid-tightseal between the outer surface of easing 4 and slip-supporting surface47 7 when the slips are actuated into casing-supporting position.

At its lower end, member 9 is provided with at least one bore, normal tolower end face 46, to accommodate a locator pin 62. Upper end face 40 ofmember 8 is provided with a generally V-shaped groove 63, correspondingprecisely to groove 33, to receive locator pin 62. The lower,horizontally disposed wall of groove 63 is formed with an upwardlyprojecting ridge or flange 64 having an upwardly opening notch intowhich the tip of locator pin 62 can fall. Locator pin 62 is againresiliently biased outwardly, in the same fashion hereinbefore describedwith reference to pin 32. When member 9 has been seated on the shoulderprovided by the upper end of member 8, with locator pin 62 disposed inthe notch in ridge or flange 64, member 9 is rotationally oriented withrespect to the member 1 in such fashion that each point on the outersurface of member 9 is coincident with a definite point on the innersurface of member 1. A plurality of through ports 65 are provided in thewall of member 1 in such locations that, when member 9 is rotationallyoriented in the manner just described, each port 65 will register with adifferent one of the ducts 59. Member 9 is provided with a pair ofvertically spaced, transversely disposed, circularly extending packings66 located to seal off the area of ports 65 when the parts are assembledas shown. The inner face of member 1 is again provided with an annulargroove extending in such fashion as to include the inner ends of ports65, so that all of these ports thus lead to a common, sealed space.

Well above shoulder 50, a through port is provided in member 9. Withmember 9 located rotationally by locator pin 62 as hereinbeforedescribed, port 67 is radially aligned with a through port 68 in thewall of member 1.

Upper hanger mandrel 11 is identical with lower hanger mandrel 10,earlier described. Thus, mandrel 11 has a downwardly and inwardlytapering bottom end face adapted to seat on shoulder 50 presented bymember 9. The lower end of mandrel 11 is internally threaded so as to berigidly connectable to the externally threaded upper end of the lastlength of easing making up casing string 4. O-ring seals are provided toeffect a fluid-tight seal between mandrel 11 and member 9 immediatelyabove shoulder 50. Mandrel 11 carries a resiliently outwardly biasedlatch pin 69, and member 9 is provided with a transverse annular grooveto receive pin 69, a stop or abutment (not shown) being provided in thegroove so that pin 69 can be engaged with the stop or abutment both torotationally position mandrel 11 and to allow the threaded joint for thehandling tool to be broken when the mandrel is installed. Mandrel 11 hasa through port 70 aligned with ports 67 and 68, as shown, so that port68 is in communication with the interior of easing string 4.

Suspension of tubing string At its top, body 1 is provided with anoutwardly projecting transverse flange 71 which is chamfered, asindicated at 72, at its upper peripheral corner. Immediately belowflange 71, body 1 is provided with an outwardly open, circularextending, transverse groove 73, the top wall 74 of which slantsdownwardly and inwardly.

Upper body member 6 is provided at its lower end with an outwardlyprojecting flange 75 of considerably greater diameter than flange 71.The outermost portion of flange 75 presents a downwardly facing,upwardly and inwardly inclined, frusto-conical guide surface 76 whichjoins an upwardly extending cylindrical surface 77, as shown. Surface 77is concentric with through bore 12 and has a diameter only slightlylarger than the diameter of flange 71. Surface 77 surrounds what may betermed a bottom face 78 which is concentric with bore 12. Adjacentsurface 77, face 78 is provided with a groove which opens downwardly andis defined by an outer cylindrical side wall, forming a continuation ofsurface 77, an inwardly andupwardly slanting wall portion 79, and ahorizontally extending annular surface 80 constituting the bottom of thegroove. At top flange 71, the inner surface of body 1 is downwardly andinwardly slanted, providing a sealing surface 81. Bottom face 78 ofmember 6 is connected to face 88 by a downwardly and inwardly slantingsurface 83, forming the inner side wall of the groove in member 6 whichaccommodates flange 71. As it slants downwardly and inwardly, surface 83diverges from surface 81, providing a space to accommodate an annularmetal sealing ring 84 which is provided for the purpose of sealingbetween the top of body 1 and the bottom of body 6.

It will be noted that the flange 75 can be considered as including anannular skirt, surrounding flange 71, the skirt having a substantialvertical dimension and projecting well below flange 71 when body 6 isseated on body 1, as shown. Thus, with the parts assembled as seen inFIG. 1, a substantial portion of the skirt surrounds but is spaced fromgroove 73. At each of three points spaced circumferentially and equallyaround flange 75, the skirt portion thereof is provided withhorizontally extending, inwardly opening bores, one of which is seen at85. Each bore 85 has an inner portion 86 of smaller diameter and anouter portion 87 of larger diameter, the two portions joining at atransverse annular shoulder 88. Disposed within each bore 85 is alatching plunger 89 having a smaller portion slidably disposed in boreportion 86 and a larger portion slidably disposed in bore portion 87,these two portions of the plunger being joined by a transverse shoulder90. A helical compression spring 91 surrounds the portion of plunger 89which is of smaller diameter and is engaged between shoulders 88 and soas to urge the latch plunger outwardly. Ducts 92 and 93 are provided,each communicating with a different end of larger portion 87 of the bore85. O-ring seals are provided on each plunger to effect a fluid-tightseal between the plunger and the wall of the bore 85 in which it isdisposed.

Each latch plunger 89 is of such length that, when hydraulic pressure isapplied to the bore via duct 92, the plunger can move to the right (asviewed in FIG. 1) and, before spring 91 becomes fully compressed, tipportion 94 of the plunger will enter groove 73. At its free end,

tip portion 94 is chamfered at an angle corresponding.

to the angle ofinclination of the top wall 74 of groove 73. Hence, whenplunger 89 is moved into full engagement in groove 73, the chamfered tipsurface of the groove comes into faceto-face engagement with wall 74-.

It will be understood that, when hydraulic pressure is applied via duct93, and fluid can exhaust from bore 85 via duct 92, the latch plungerwill be moved to the left until it is fully retracted, that is, untilthe tip thereof is wholly within bore 85. With the latch plungers all inthis position, it will be obvious that body 6 can be lowered to seatupon the upper end of body 1, guide surface 76 serving to center body 6with respect to body 1. As body 6 is lowered, the skirt portion ofbottom flange 75 thereof descends into surrounding relation about flange71 and groove 73, and surface 80 comes into faceto-face engagement withthe annular top face of flange 71. When member 6 has been fully loweredinto position, hydraulic pressure can then be applied via duct 92,causing the latch plungers to move inwardly until their inner tipsengage in groove 73. In this connection, the chamfer at the tip of eachplunger engages downwardly and inwardly slanting wall 74, so that atight compressive fit is provided between flange 71 and the groovedefined by surfaces 79, 80 and 83. As body 6 becomes fully seated onbody 1, seal 84 is placed under great compression between surfaces 81and 83, so effecting a good fluid-tight seal between the two bodies.

The lower end portion of body 6 is provided with a centrally locateddependent portion 95. Within portion 95, bore 12 is provided with adownwardly and inwardly slanting shoulder portion 96. Tubing string 5 issupported from shoulder portion 96 by hanger element 13, which has anupper end portion of a larger diameter, to fit Within the main portionof bore 12, a lower end portion of smaller diameter, and an intermediateportion tapering inwardly and downwardly to come into face-to-facecontact with shoulder portion 96. The lower end portion of hangerelement 13 is internally threaded for attachment to the externallythreaded upper end of tubing string 5. Element 13 is provided with anintermediately located groove carrying an O-ring sealing element toestablish a fluid-tight seal between element 1 3 and shoulder portion96. It will be understood that the bore 12 can freely pass tubing string5 and that the tubing string can 'be suspended simply by attachinghanger element 13 to the last section of tubing installed, so that thehanger element comes into seated relation in member 6 as the tubingstring is finally lowered.

Upper body 6 can be of any suitable configuration and, in accordancewith the usual practice, will support an additional head member ormembers, as indicated at 97. The head member next above body 6 can belatched in place thereon by means of latching plungers, provided in thesame fashion hereinbefore described with reference to latching plungers89.

Assembled in the manner illustrated in FIGS. 1 and 1A, the well headconstruction of this embodiment operates to suspend the tubing stringand casing strings 3 and 4 from hanger elements which are of the mandreltype and which are seated directly on rigid shoulders afforded by theupper and lower bodies and the upper and lower tubular hanger members.To attain the assembly illustrated in FIGS. 1 and 1A, it is of coursenecessary that the casing strings 3 and 4 descend to the desired,predetermined depth, without jamming. Thus, under normal circumstances,all of the tubular strings will be supported by mandrel type elementsand the two sets of slips will remain inactive, the slip segments 25 and51 retaining their disengaged position, as illustrated in FIG. 1A.

Assume, on the other hand, that hanger mandrel 10 has been attached tothe upper end of the last piece of casing in casing string 3 but that,as the casing string is then further lowered, the string becomes jammedbefore the hanger mandrel can seat on shoulder 20 of member 8. Thiscondition is easily detected because the latch pin 43 will not haveengaged in groove 44 and application of an upward strain to the casingstring is effective to raise the string. Under these circumstances, itis necessary to provide support for the casing string, sever the stringjust below the hanger mandrel in order to recover the latter, and thenpack off the casing string. In order to accomplish this in accordancewith the embodiment of the invention illustrated in FIGS. 1-7, the slipassembly comprising slip segments 25 is first actuated by supplyinghydraulic pressure, via ports 35 and ducts 22, to actuate plungers 21downwardly, driving the slip segments 25 downwardly along supportingsurface 17, shear pins 30 being ruptured in the process, and the slipsegments ultimately coming into a position such that the working faces26 thereof are positively engaged with the adjacent outer surface of thetubing string. Slip segments 25 are thus caused to be wedged betweencasing 3 and the slip-supporting surface 17, so that the slips supportthe weight of the casing in conventional fashion.

A casing cutting tool is then run down and, being first located relativeto the top of member 8 in such fashion that the cut will be just belowports 38 and 39, is operated to cut through the casing so that hangermandrel 11 can be recovered. A seal, indicated generally at 98, andshown in detail in FIG. 7, is then lowered into place and set to packoff the upper end of casing 3, providing a fluid-tight seal between thecasing and member 8.

Seal 98 comprises a lower annular member 99 having a downwardly andinwardly slanting surface 100, FIG. 7, of such shape and disposition asto be engageable in face-to-face relation with the shoulder 20 presentedby member 8. Lower member 99 has a flat annular upper face 101 andcylindrical outer and inner surfaces 102 and 103, respectively. Theradial thickness of annular member 99 is only slightly less than thespacing between the adjacent inner face of member 8 and the outersurface of casing 3. At its upper, inner edge, member 99 is providedwith an annular notch defined by plain cylindrical surface 104 anddownwardly and inwardly slanting surface 105, surfaces 104 and 105 beingconnected by a transverse or horizontal surface 106. At its upper end,member 99 is provided with a p'urality of circumferentially spaced,upwardly opening, vertical bores 107.

Seal 98 also comprises an upper annular member 108 which is considerablyelongated as compared to lower member 99. Upper member 108 has a plaincylindrical inner surface 109 and a flat, annular, transverse bottomface 110 disposed above face 101 of member 99. At its lower inner edge,member 108 is provided with an annular transverse notch defined byupright cylindrical surface 111 and upwardly and inwardly slantingsurface 112, surfaces 111 and 112 being joined by an intermediatetransverse surface 113. A plurality of vertical, downwardly opening,circu-mferentially spaced bores 114 are provided in member 108 tocooperate with bores 107 in member 99. The circumferential spacing ofbores 114 and 107 is identical, so that pairs of the bores may bevertically aligned as shown in FIG. 7. In alternate pairs of bores 107,114, there are disposed helical compression springs 115. Headedretaining studs 116 are disposed in the remaining pairs of bores 107,114, retaining pins 117 being carried by member 108 and projecting eachinto a different bore 114 to engage below the heads of studs 116 andthereby limit the space between faces 101 and 110 to a distance lessthan the relaxed length of springs 115.

A packing ring 118, deformable under compression, is disposed in thespace between surfaces 105 and 106, on the one hand, and 112 and 113, onthe other hand. In transverse cross section, packing ring 118 has thegeneral configuration of a T, the arms forming the crossbar of the Tprojecting into contact with the slanting surfaces 105 and 112,respectively, and the end of the stem of the T being engaged withsurfaces 104 and 111, the width or vertical dimension of the packingring being such that, when the ring is relaxed, the same will bridge thegap between faces 101 and 110 when the heads of studs 11 6 are engagedwith retaining pins 117, as seen in FIG. 7.

The lower portion of member 108 has the same radial thickness as lowmember 99. The upper portion of member 108, however, is substantiallythinner and includes an outer surface portion 119 which is exteriorlythreaded at the upper end of member 108 for engagement with the interiorthreads of a setting tool 120, FIG. 7. At its upper end, member 108 isprovided with an outwardly and downwardly slanting surface 121 servingas a guide for the tip of the setting tool 120. Below the exteriorlythreaded portion, the wall of member 108 is provided with a lateral port122 which, as will be explained, is adapted for alignment with port 39in member 8 when the seal 98 is set.

In its lower portion, member 108 is provided with an outwardly openingcylindrical recess 123 in which is slidably disposed a latch pin 124. Anaxial bore is provided in the inner end face of latch pin 124 andaccommodates a compression spring 125 which, engaged between the latchpin and the bottom end wall of recess 123, urges latch pin 124outwardly. Latch pin 124 is held in recess 123 by a suitable retainingmember 126.

Assuming that casing 3 has been severed in the manner hereinbeforedescribed and that setting tool 120 has been attached to seal device 98,it will be obvious that the setting tool can be manipulated to lower theseal until bottom face 100 thereof engages shoulder 20 on member 8.Further lowering of the setting tool will then cause springs and packingring 118 to be compressed to such an extent that faces 101 and 110 comeinto flush engagement. As will be clear from a comparison of FIGS.

6 and 7, the vertical distance between shoulder 20 and latch pin 124,when faces 161 and 110 are engaged, is substantially equal to thevertical distance between shoulder 26 and groove 44. Hence, lowering theseal, by manipulation of setting tool 120, to such an extent as to causethe seal to seat on shoulder 20 and faces 101 and 116 to come intocontact, will result in latch pin 124 snapping into groove 44. Suchengagement of pin 124 in groove 44 serves both to retain seal 98 in itsset position and to rotationally locate the seal in such manner thatport 122 is aligned with port 39. Engagement of latch pin 124 in groove44 holds upper member 166 of the seal device rigidly in place withrespect to member 8, because of the radial stop in groove 44 engaged bypin 124, so that settling tool 120 can now be detached from the sealdevice and withdrawn upwardly.

Referring to FIG. 6, it will be apparent that a closed annular space isdefined by the outer surface of casing 3, cooperating with surfaces164-106 and 111-113. The transverse cross section of this annular spaceis substantially smaller than the transverse cross-sectional area of thepacking ring 118 when the packing ring is relaxed. Hence, when sealdevice 98 is set as hereinbefore described, so that the parts thereofoccupy the positions seen in FIG. 6, packing ring 118 is compressivelydeformed and provides a fluid-tight seal between members 99 and 108 andthe outer surface of the adjacent casing 3. Both members 99 and 163 areprovided with outwardly opening transverse annular grooves which receiveO-ring packing elements 127 and 126, respectively, which provide afluidtight seal between the outer surfaces of seal device 93 and theadjacent inner surface presented by member 8.

From FIG. 6, it will be apparent that ports 122 and 39 place theinterior of casing 3 in substantially direct communication with port 38in body 1.

Referring again to FIG. 1A, it will be seen that body 1 and hangermember 8 combine to form support means from which casing 3 is suspended,the passage through the hanger member including both the slip-supportingsurface 17 and the seat 20. While this construction is advantageous forcertain well installations, it will be understood that the invention isnot limited to constructions in which the hanger is an element separatefrom the body member.

It is also to be understood that the invention can be practiced withvarious types of pack-off devices instead of that illustrated in FIG. 7,Thus, for example, pack-off devices such as those described in detail incopending application Ser. No. 302,994, filed Aug. 19, 1963, by EdwardE. Castor et al., can be employed.

What is claimed is:

1. Wellhead apparatus adapted for installation under water, comprisingin combination support means adapted to be installed under water anddefining an upright passage dimensioned to pass a pipe to be suspendedfrom said support means,

said passage being defined in part by a downwardly and inwardly taperingslip-supporting surface,

said passage including an upwardly facing transverse seat located abovesaid slip'supporting surface;

a plurality of slip segments operatively carried by said support meansfor movement between a raised inactive position, in which said segmentsare spaced outwardly from the pipe to be supported when the pipe isdisposed within said passage, and a lowered active position on saidslip-supporting surface, in which position said segments willoperatively engage the pipe to support the same;

means carried by said support means for releasably retaining said slipsegments in said raised inactive position;

power means carried by said support means and operatively arranged toactuate said slip segments from said raised inactive position to saidlowered active position;

a pipe suspending member adapted to be secured to the well pipe anddimensioned for downward insertion into said passage,

said suspending member having a downwardly facing surface dimensionedfor engagement with said seat;

means operative for determining, from a point remote fro-m theunderwater location of said support means, whether or not saidsuspending member is disposed with said downwardly facing surface inengagement with said seat; and

a unitary annular packing device dimensioned for downward insertion intosaid passage into engagement with said seat .to seal between saidsupport means and the pipe to be suspended when, the pipe having failedto descend far enough for engagement of said suspending member with saidseat, said slip segments are actuated into engagement with the pipe bysaid power means and said suspending member is then removed.

2. Wellhead apparatus according to claim 1 and wheresaid support meanscomprises a body member having upright passage means therethrough, and

a hanger member dimensioned for downward insertion into the passagemeans of said body member,

said body member and hanger member having cooperating shoulder meansoperative to support said hanger member on said body member,

said hanger member defining said upright passage and including saidslip-supporting surface and said seat.

3. Wellhead apparatus according to claim 2 and Wheresaid hanger memberincludes a portion disposed above said slip-supporting surface andprojecting inwardly from the top thereof, said portion being providedwith a plurality of downwardly extending bores,

said power means comprises a plurality of pistons each slidably disposedin a different one of said bores and operatively arranged relative toone of said segments to force the same downwardly as the piston is moveddownwardly in its bore, and

said means for operating said power means includes a plurality of ductsin said hanger member each communicating with a different one of saidbores above the corresponding one of said pistons and opening outwardlytoward said body member, and duct means provided in said body member andcommunicating with said ducts for supply of pressure fluid thereto whensaid hanger member is supported on said body member by said shouldermeans.

4. Wellhead apparatus according to claim 1, wherein said means operativefor determining whether or not said suspending member is disposed withsaid down wardly facing surface in engagement with said seat comprisesan inwardly opening detent groove in said support means, said grooveopening into said passage and being located above said seat,

at least one detent member carried by said suspending member andarranged for movement between a retracted position and a laterallyprojected position, said detent member being aligned with said groovewhen said suspending member is disposed with said downwardly facingsurface in engagement with said seat, and

means carried by said suspending member for actuating said detent memberoutwardly into engagement in said groove.

3,336,976 13 5. Wellhead apparatus according to claim 4, wherein saidpacking device comprises a lower annular member engageable with saidseat, an upper annular member arranged above said lower annular member,said lower and upper 5 annular members cooperating to define an inwardlyopening annular packing-accommodating space, an annular packing elementdisposed in said packing-accommodating space, 10

said lower and upper annular members being rela- 2,312,487 tivelymovable axially of said packing device, 2,689,139 at least one detentmember carried by said upper 2,897,895 annular member and arranged formovement 2,990,851 between a retracted position and a laterally pro- 153,084,745 jected position, and 3,090,640 means carried by said upperannular member for 3,127,197 actuating said detent member outwardly into3 137 34 engagement in said groove,

the dimensions of said annular members and said packing element, and thelocation of said detent member on said upper annular member,

being such that, when said lower annular member is engaged with saidseat and said upper annular member is so positioned that said detentmember engages in said groove, said packing element is compressivelydeformed by said lower and upper annular members.

References Cited UNITED STATES PATENTS 20 CHARLES E. OCONNELL, PrimaryExaminer.

R. E. FAVREAU, Assistant Examiner.

1. WELLHEAD APPARATUS ADAPTED FOR INSTALLATION UNDER WATER, COMPRISINGIN COMBINATION SUPPORT MEANS ADAPTED TO BE INSTALLED UNDER WATER ANDDEFINING AN UPRIGHT PASSAGE DIMENSIONED TO PASS A PIPE TO BE SUSPENDEDFROM SAID SUPPORT MEANS, SAID PASSAGE BEING DEFINED IN PART BY ADOWNWARDLY AND INWARDLY TAPERING SLIP-SUPPORTING SURFACE, SAID PASSAGEINCLUDING AN UPWARDLY FACING TRANSVERSE SEAT LOCATED ABOVE SAIDSLIP-SUPPORTING SURFACE; A PLURALITY OF SLIP SEGMENTS OPERATIVELYCARRIED BY SAID SUPPORT MEANS FOR MOVEMENT BETWEEN A RAISED INACTIVEPOSITION, IN WHICH SAID SEGMENTS ARE SPACED OUTWARDLY FROM THE PIPE TOBE SUPPORTED WHEN THE PIPE IS DISPOSED WITHIN SAID PASSAGE, AND ALOWERED ACTIVE POSITION ON SAID SLIP-SUPPORTING SURFACE, IN WHICHPOSITION SAID SEGMENTS WILL OPERATIVELY ENGAGE THE PIPE TO SUPPORT THESAME; MEANS CARRIED BY SAID SUPPORT MEANS FOR RELEASABLY RETAINING SAIDSLIP SEGMENTS IN SAID RAISED INACTIVE POSITION; POWER MEANS CARRIED BYSAID SUPPORT MEANS AND OPERATIVELY ARRANGED TO ACTUATE SAID SLIPSEGMENTS FROM SAID RAISED INACTIVE POSITION TO SAID LOWERED ACTIVEPOSITION; A PIPE SUSPENDING MEMBER ADAPTED TO BE SECURED TO THE WELLPIPE AND DIMENSIONED FOR DOWNWARD INSERTION INTO SAID PASSAGE, SAIDSUSPENDING MEMBER HAVING A DOWNWARDLY FACING SURFACE DIMENSIONED FORENGAGEMENT WITH SAID SEAT; MEANS OPERATIVE FOR DETERMINING FROM A POINTREMOTE FROM THE UNDERWATER LOCATION OF SAID SUPPORT MEANS, WHETHER ORNOT SUSPENDING MEMBER IS DISPOSED WITH SAID DOWNWARDLY FACING SURFACE INENGAGEMENT WITH SAID SEAT; AND A UNITARY ANNULAR PACKING DEVICEDIMENSIONED FOR DOWNWARDLY INSERTION INTO SAID PASSAGE INTO ENGAGEMENTWITH SAID SEAT TO SEAL BETWEEN SAID SUPPORT MEANS AND THE PIPE TO BESUSPENDED WHEN, THE PIPE HAVING FAILED TO DESCEND FAR ENOUGH FORENGAGEMENT OF SAID SUSPENDING MEMBER WITH SAID SEAT, SAID SLIP SEGMENTSARE ACTUATED INTO ENGAGEMENT WITH THE PIPE BY SAID POWER MEANS AND SAIDSUSPENDING MEMBER IS THEN MOVED.